Sleep
Conditions
Keywords
Saffron extract, Sleep quality, Insomnia, Actigraphy, Nutraceutical, Randomized clinical trial
Brief summary
This randomized, triple-blind, placebo-controlled clinical trial aims to evaluate the effects of daily saffron extract supplementation (30 mg/day) for six weeks on objective and subjective sleep quality in middle-aged adults with mild-to-moderate sleep disturbances. Secondary outcomes include heart rate variability, cognitive processing speed, emotional state, perceived health status, and biochemical stress markers.
Detailed description
Sleep disturbances are highly prevalent in middle-aged adults and are associated with impaired daytime functioning, increased cardiometabolic risk, and reduced quality of life. Pharmacological treatments may be effective but are often associated with adverse effects and dependency risk. Saffron (Crocus sativus L.) contains bioactive compounds such as crocins and safranal, which may modulate neurotransmitter systems involved in sleep regulation, including serotonin, dopamine, and GABA pathways. Eighty middle-aged adults with mild-to-moderate sleep disturbances will be randomly assigned to receive either 30 mg/day of standardized saffron extract or placebo for six weeks. Sleep will be objectively assessed using wrist-worn accelerometry over 14 days before and during the final weeks of intervention. Subjective sleep quality will be evaluated using validated questionnaires. The study follows CONSORT guidelines and will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice standards.
Interventions
DIETARY_SUPPLEMENTSaffron Extract
Participants will receive 30 mg/day of standardized saffron extract (≥3% crocins; ≥2% safranal) for six weeks. Capsules will be taken once daily, one hour before bedtime.
DIETARY_SUPPLEMENTDietary Supplement: Placebo
Participants will receive identical capsules containing maltodextrin and excipients for six weeks, taken once daily one hour before bedtime.
Sponsors
Universidad de Granada
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
Saffron extract and placebo capsules will be identical in appearance, taste, packaging, and labeling. Allocation will be performed by an independent third party. Participants, investigators, care providers, and outcome assessors will remain blinded until study completion.
Intervention model description
Participants will be randomly assigned in a 1:1 ratio to receive either saffron extract (30 mg/day) or placebo for six weeks.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18-65 years * Mild-to-moderate sleep disturbances * BMI between 18 and 35 kg/m² * Not receiving active pharmacological or psychological treatment for sleep disorders * Willingness to comply with study procedures
Exclusion criteria
* Severe neurological, psychiatric, or cardiovascular disorders * Diagnosed with obstructive sleep apnea, treated with CPAP * Night shift workers * Use of medications or supplements affecting sleep * Recreational drug use * Pregnancy or breastfeeding * Uncontrolled medical conditions
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Objective Sleep Efficiency (%) | Baseline and Week 6 | Measured by wrist actigraphy over 14 consecutive days before intervention and during weeks 5-7 of supplementation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Total Sleep Time (hours) | Baseline and Week 6 | Objectively measured total sleep time (in hours) assessed using wrist-worn triaxial accelerometry over 14 consecutive days. Data will be processed using validated algorithms integrating movement patterns and sleep diaries. |
| Wake After Sleep Onset (minutes) | Baseline and Week 6 | Wake After Sleep Onset (WASO), defined as the total number of minutes awake after initial sleep onset, measured objectively by wrist actigraphy over 14 consecutive days. |
| Sleep Latency (minutes) | Baseline and Week 6 | Sleep latency, defined as the time (in minutes) from reported bedtime to sleep onset, measured objectively using wrist-worn accelerometry and participant sleep logs. |
| Pittsburgh Sleep Quality Index (PSQI) Score | Baseline, Week 4, and Week 6 | Subjective sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated questionnaire that evaluates sleep quality over the previous month. Total score ranges from 0 to 21, with higher scores indicating poorer sleep quality. |
| Insomnia Severity Index (ISI) Score | Baseline, Week 4, and Week 6 | Severity of insomnia symptoms assessed using the Insomnia Severity Index (ISI). Total score ranges from 0 to 28, with higher scores indicating greater insomnia severity. |
| Epworth Sleepiness Scale (ESS) Score | Baseline, Week 4, and Week 6 | Daytime sleepiness assessed using the Epworth Sleepiness Scale (ESS). Total score ranges from 0 to 24, with higher scores indicating greater daytime sleepiness. |
| Heart Rate Variability (RMSSD and SDNN) | Baseline and Week 6 | Cardiac autonomic modulation assessed through heart rate variability (HRV) analysis under resting conditions. Time-domain parameters include RMSSD (root mean square of successive differences) and SDNN (standard deviation of normal-to-normal intervals), measured during a 5-minute stable segment. |
| Emotional State (BDI-FS, STAI, PSS-10 Scores) | Baseline, Week 4, and Week 6 | Emotional status assessed using validated psychometric instruments: Beck Depression Inventory-Fast Screen (BDI-FS) State-Trait Anxiety Inventory (STAI) Perceived Stress Scale (PSS-10) Higher scores indicate greater depressive symptoms, anxiety, and perceived stress, respectively. |
| Health-Related Quality of Life (SF-36 Score) | Baseline, Week 4, and Week 6 | Health-related quality of life assessed using the Short Form-36 Health Survey (SF-36), which evaluates physical and mental health domains. Scores are standardized from 0 to 100, with higher scores indicating better perceived health status. |
| Biochemical Stress Markers (Cortisol, ACTH, Glucose, Insulin) | Baseline and Week 6 | Biochemical markers related to stress and metabolic function, including serum cortisol, adrenocorticotropic hormone (ACTH), fasting glucose, and insulin levels, obtained from clinical records and laboratory analyses. |
Contacts
CONTACTLucas Jurado-Fasoli, PhD
Outcome results
None listed